We studied how the 2021 total solar eclipse over Antarctica affected the upper atmosphere near the South Pole. Using HF radars, we observed changes in radio wave behavior and fast plasma flows in the ionosphere, including sudden high-velocity echoes that tracked the eclipse shadow. Satellite data and models revealed changes in ionospheric currents and conductance. These findings show eclipses can temporarily reshape magnetosphere-ionosphere interactions at polar latitudes.

We created a new long-term record of upper atmosphere winds using data from a global network of radars spanning more than 30 years. Because these measurements do not directly show altitude, we developed a method to estimate where the signals come from and tested it against other observations and models. The results show good agreement, meaning these data can now be used with greater confidence to study atmospheric motion and its effects on communication and space systems.

Sub-auroral polarisation streams (SAPSs) are very fast plasma flows that occur at mid-latitudes, which can affect the atmosphere. In this paper, we use four ground-based radars to obtain a wide coverage of SAPSs that occurred over the USA, along with interferometer cameras in Virginia and Massachusetts to measure winds. The winds are strongly affected but in different ways, implying that the balance forces on the atmosphere is strongly dependent on proximity to the disturbance.